Objective: To detect the cDNA sequence of immunoreactive growth hormone (irGH) in human lymphocytes and to compare it with that of human growth hormone (hGH) in the pituitary.
Methods: The mRNA of irGH in human peripheral blood mononuclear cells (PBMC) was detected by Northern blot analysis. The cDNA of irGH was obtained by reverse-transcriptase and polymerase chain reaction amplification and obtained by screening from a cDNA library of human T lymphocytes. The sequence of irGH cDNA was determined and compared with that of the pituitary hGH.
Results: Very low level of irGH mRNA was detected in human PBMCs by Northern blot analysis. The cDNA sequence of the entire open reading frame of human irGH was 651 bp, which is identical to that of pituitary hGH.
Conclusions: The same hGH molecule can be produced by human pituitary somatotrophic cells and human peripheral lymphocytes.